NotchLC was created to be a GPU powered codec that provided the quality needed to be an intermediary codec as well as the performance required to be a playback codec. You can read more about it on the NotchLC website.
It brings the equivalent of 10bit accuracy in a scrubbable codec (with 12bit of Luma data) that is extremely fast to encode and decode, with a compression ratio of 8:1 to 4:1.
Luma, Chroma, Bit Depths & Compression #
The LC in NotchLC stands for Luma & Chroma. NotchLC breaks colour data down into luma and chroma (YUV). 12bits of depth are assigned to luma data, as in many scenarios this is where bit depth is most perceivable. 8bits are assigned to each of the U & V channels. Total (28 bits per pixel). Alpha data is stored at 8bit depth.
Software support #
NotchLC is currently supported in:
- Notch Builder 0.9.22 and later
- Adobe CC 2018 / 2019 (After Effects, Premiere, Media Encoder) via our Adobe CC Plugin
- Legacy QuickTime 7 Windows
- disguise r16.0
Quality Levels & Bit Rates #
Rather than specify target bitrates and end up with undetermined quality outcomes, NotchLC takes the reverse approach. When encoding you set a quality level, which is essentially an allowable error level in encode. The encoder then searches for best fit compression in each block that meets this quality threshold. These defined coefficients of error give confidence in the quality of the resulting encoded video.
Typically, NotchLC users are seeing compression ratios between 4:1 and 8:1 when compared to raw video. And as a general rule of thumb Notch (at Optimal Level) tends to be 30% larger than HAPQ (for a significant quality uplift).
NotchLC provides five quality levels:
- Very Good
Optimal is your go-to quality level and fit for most day-to-day purposes. It is the sweet spot of file size and quality. If you utilise Best you may see significantly larger file sizes for only marginal gains in quality (which can in some cases be desirable, but overall we recommend Optimal for most uses.)
Bit rates of the individual Y, U, V and Alpha channels are not affected by the different quality levels. NotchLC always uses 12bits of depth for luma, and 8bits for the U, V and alpha channels respectively.